Hypercalcemia of malignancy remains a common metabolic complication of advanced cancer often resulting in considerable morbidity and diminishing life quality in the later stages of disease. Bisphosphonates, especially zoledronic acid, are potent inhibitors of bone resorption and are the most effective therapy for hypercalcemia of malignancy. We report on the course of disease in a 51-year-old woman who presented with metastatic breast cancer that had relapsed to the liver. The patient suffered from a pamidronate-refractory paraneoplastic hypercalcemia, which caused a confused mental status and compromised her already severely limited life quality. Only with the introduction of zoledronate could the patient's hypercalcemia be normalized with consecutive regain of an acceptable life quality.